Gear checking apparatus



Dec. 30, 1952 A. s. ORL/AND1 2,623,295

- GEAR CHECKING APPARATUS Filed Apml 1s, 194e v sheets-sheet 2 @E MAL/a@ Dec. 30, 1952 A. s. oRLANDl 2,523,295

GEAR CHECK-[NG APPARATUS Fine@ April 18, 194e 'I sheets-sheet s m JNVENTOR.

zver'zca 5 0/-2427475 A. s. ORLANDI GEAR CHECKING APPARATUS Dec.l 30, 1952 7 Sheets-Sheet 4 Filed April 18, 1946 BY, M24-v irra/WYEVS,

Iee. 3G, 1952 A. s. oRLANDl 2,623,295

GEAR QHCKING APPARATUS FiVledrApril 18. 1946 7 Sheets-Sheet 5 IN V EN TOR.

Dec. 3G, 1952 A. s. ORLANDI 2,623,295

GEAR CHECKING APPARATUS Dec. 30, 1952 A. ls. oRLANDl 2,623,295

GEAR CHECKING APPARATUS Filed April 18, 1946 '7 Sheets-Sheet 4" INVENTOR.

Patented Dec. 30, 1952 UNITED STATES `PATENT OFFICE GEAR CHECKING APPARATUS,

America S'. Orlandi, Detroit, Mich. Appliaftih April 13, 1946, Serial N; r663,147

6 Claims. 1

This invention relates to gear checking apparatus, and has particular relation `to a gear checker in which the gear to` be checked may be positioned between laterally spaced anvils adapted to mount rolls' capable of entering between the flanks of thegeai teeth for checking the pitch diameter of such gear.

lt is conventional practice to check the pitch diameter of gears by niean's of a micrometer and a pair of rolls. ln such practice, it is very difcult to hold the rollsl position while setting the micrometer, andit is also extremely difficult to locate the high point ontlie diameter of the rolls. Another diliiculty, is the human element which .enters into checking gears in this manner. inasmuch as the operator is requiredto feel when the micrometer is properly set, it is readily apparent that each operator will differ to some ex-` tent, even with experience; This results in dif' ferent readings on identical gearswhen taken by diierent operators.

It is therefore, a primary object of the present invention to provide a gear checking apparatus in which a gear tobef checked may be positioned between rolls carried by anvils Whichhave been accurately and precisely located [in predetermined position vbefore the rolls are nxedthereto.

Another object or thepresent invention is to provide apparatus for checkingV gears which a gea-r to be checked may be `positioned between rolls which are adapted `to exert a uniform pressure against the Hanks or the gear teeth as said rolls enter diametrically opposed interdental spaces on such gear.

Another object of the invention is to provide a gear checker having opposite, movable anvils with flat faces adaptedF to receive therebetween gage blocks to accurately andgp-recisely position the same in predetermined adjusted position while a roll-irnounting means on each anvil is in position.

A further objectV of the present invention is to provide gear checking Ine-ans in which a1 mandrel for supporting a gear to be checked may `be accurately and precisely positioned from a rollsupporting anvil,` while the meansfor mounting the roll to the anvil 1is in position on-said anvil.

A further object of thisinventionis to provide in a gear checkingapparatus means for 1nount ing a roll to each of a pair oflatia'ced, opposite; movable anvils whichv means also provides for supporting a gear to bech'eckfed-as the rolls' enter diametrically opposed `intindent-,aflspaces in the gear.

(o1. ege-17915)" Still further, the checking device of the pres ent invention contemplates Athe provision of ap# paratus from which gear checking rolls may be removed for checking gear blanks or other parte between flat-face. opposed anvils.

A still further object of the present invention is to provide gear checking apparatus for checking parallelism of gearteeth.

A still further obje'ctyof-v the present invention is to provide a gear clieclcinugA apparatus of the character described for checking pitch diameter of aV gear Whichrnay beA readily and quickly modified for checking eccentricity or backlash and which may be operated by semi-skilled or relatively unskillecllabor to accomplish such gear checking with extreme accuracy.

Further objects and advantages of the invention will be apparent from the description which follows, and construed in connection with the accompanying drawings `in which like `numerals indicate like parts wherever shown and wherein:

Fig. 1 is a plan view of a gear checking apparatus embodying the improvements of the present invention;V g y Fig. 2 is a front, sectional elevation or the apparatus of Fig.` 1;

Figure 3 is a transverse section taken substantially on line 3.-'3 of Fig. 2, illustrating the driving means for the slidable carriages;

Fig. e is a transverse section taken on line li-[i of Fig. 2, illustrating the means for shifting the left-hand anvil carriages onl the main left-hand carriage;

Fig. 5 is a broken plan View illustrating the gear checking apparatus as altered for checking concentricity of a gear;`

Fig. 6 is a longitudinal section taken on line 8 6 of Fig. 5, illustrating the gear held in position by a mandrel as' the `saine is checked for concentricity;

Fig. 7 is a broken, plan view of the gear checking apparatus altered for checking backlash of a gear, in which one of the anvils is replaced with a movable lever and indicating dial;

Fig. v8 is a section taken on line 8-3 of Fig. '7, illustrating the gea-r heldV in'position by a man drel as the lever engages the ilanks thereof while checking backlash;

Fig. 9 is a partial; sectional elevation showing themeans for checking pitch diameter of a Wide gedar `with `a shaft'outwardly directed from each s1 e;

Fig. 10 is a sectional elevation illustrating a wide-.faced gear with an outwardly directed shaft on eachside being checkedfor concentricity;

aecaccs Fig. l1 is a perspective view of a jaw adapted to support a ball;

Figs. 12 to 14 inclusive are views of a double jaw adapted to support a circular gaging body;

Figs. 15 to 17 inclusive yare views of a single jaw for supporting a circular gaging body;

Figs. 18 and 19 are views of a flat face anvil for use with the gear checker of this invention;

Figure 20 is a broken plan view of a modication of the invention illustrating another form of slide on the left end of the machine;

Figure 21 is a sectional elevation taken substantially along line 2I-2I of Figure 2i) and illustrating the apparatus for checking the parallelism of gear teeth;

Figure 22 is a transverse section taken on line 22-22 of Figure 21 showing the pivotally supported curved levers which actua-te the indicator;

Figure 23 is a broken plan view of the modiiication shown in Figure 20 with a sleeve and indicating arm assembly in position for checking the backlash of a. gear;

Figure 24 is a sectional elevation taken substantially on the line 2li-2d of Figure 23 showing the backlash indicating arm in contact with one of the curved levers adapted to `transmit movement of the arm to the indicator;

Figure 25 is a perspective view or" the curved levers for actuating the indicator;

Figure 26 is a perspective view illustrating the assembly for imparting rotative movement of a roll contacting the gear tooth ilanks to one of the curved levers of Figure 25; and

Figure 27 is a plan view of a. modified form oi indicating arm for use with the backlash checking sleeve.

In the machine of this invention, ltwo main carriages are slidably positioned on a base in lateral spaced relationship. Each of said carria-ges provides for slidably mounting on the up per surface thereof anvil-supporting slides. Such anvils are maintained in a lateral, spaced relationship with respect to each other and adapted to mount jaws carrying rolls capable of entering between iianks of gear teeth. These anvils may be accurately and precisely spaced a predetermined distance apart before the gear checking operation takes place. When the anvils have thus been positioned, each of the main carriages is rigidly and positively locked in position. One oi the anvil supporting slides is also locked in position while the other is resiliently held by spring means. A rotatable eccentric is provided `to laterally move this slide in order that the gear to be checked may be introduced between said rolls. After the gear is introduced between said rolls, the eccentric is again turned permitting the spring means to resiliently urge the rolls on said anvils to enter diametrically opposed interdental spaces of such gear. In this manner, the gear to be checked is held between the rolls and any diierences in such diameter read upon the scale of an indicator provided on said resiliently held anvil carriage.

In order to check a gear for concentricity in this gear checking apparatus,.a mandrel is placed in a central opening in the base of the machine. The gear to be checked is mounted on said mandrel in position to permit the roll on the springloaded slide to enter into a tooth space on the gear. With the gear thus supported, it may be rotated and the variations in concentricity thereof read on the dial of the indicator.

It is also possible to check the backlash of the gear in the gear checking apparatus of this in- 4 vention by replacing the rigidly held anvil with a centrally pivoted lever adapted to engage an indicating means. rihe gear to be checked is mounted on the mandrel in such position that the roll associated with the spring-loaded slide may fully enter the tooth space on the gear. Such roll is then backed oi' the desired amount, which amount represents the correct backlash, and the gear is oscillated as one end of the pivotally mounted lever is permitted to engage a flank of a tooth on the opposite side of the gear. The extent of such oscillation is read on the dial of the indicator, contacted by the other end of the lever, and any error may be readily detected.

In order to describe the invention more fully, reference is made to the figures in which a base is generally indicated at I. This base may be of hollow, integral construction with a downwardly directed skirt-like portion 2 tc house certain of the apparatus interiorly therein. Such skirt portion 2 may be of suitable height and provided with a foot 3 kto adapt the checking apparatus to be mounted upon a base or table such :as may be found in any shop. This base is provided with a lip l extending around its upper portion and has a table-like portion 5 integral with such skirt-like wall 2.

On the table portion 5, machined surfaces are provided at 6 and 1, as may be seen in Fig. 3, to serve as rails for slidably receiving the main carriages 8 and 9, respectively. The inner face of the lip ll is machined to form a surface perpendicular to rail 6 at the left side, and to rail 'I on the right side, for holding said carriages against side movement. A keeper bar III is anchored to lip 4 on the left. and another keeper bar II anchored to lip 4 on the right side of the apparatus. These bars overlie shoulders I2 and I3, respectively, on carriage 8, and shoulders I 4 and I5, respectively, on carriage 9, to positively secire said carriages for sliding movement on the rai s.

This sliding movement of the carriages is eifected by rack I6, anchored to depend centrally from the lower surface of carriage 8, and rack I'I anchored to similarly depend from the lower surface of carriage 9.

A trough-like depression I8 is provided in table 5, immediately below carriage into which rack IG is permitted to extend to mesh gear I9. Such gear is rotatably supported by an integral shaft 25) `iournaled for rotation in bearing 2 I. An opening 22, provided in the lower surface of depression I8, permits gear I9 to mesh rack I6 in this manner.

Below carriage 9, a similar trough-like depression 23 is provided into which rack I I extends to mesh gear 24. Such gear is rotatably supported upon shaft 25 journaled for rotation in a bearing, not shown, but which is identical to bearing 2|. An opening 26 in depression 23 permits gear 24 to extend therethrough for mating rack Il.

Rotation yof gear I9 is accomplished by gear 21 which is on the opposite end `of shaft 20. Gear 27 is spaced from bearing 2l by means of bushing 23 and held to said shaft 2i] by means of nut 29 which threadably engages the adjacent portion of such shaft. It will be observed that an integral embossment is formed at the side of gear I9, which embossment denes a radial annular shoulder 30. When such nut 29 is drawn tightly against the face of gear 2l, shoulder 3E! on such shaft 2i) is drawn against an adjacent face of bearing 2|, securing gears i9 and 21 against longitudinal movement.

Rotation of gear24 is accomplished byV gear 3| fixed to shaft 25. This'gear meshes a wide-face gear 32 which is rotatably supported upon shaft 33 journaled for rotation in bearing 34; An elongated rackv 35 extends between gears 21 and 32, meshing said gears. It is pointed ou'tthat' the width of the teeth of gear32`is sufficient to permit such gear to mesh gear 32 and rack 35;

Obviously, as rotation of gear 32 isl effectedV by means of shaft 33, which has a convenientlyr accessible handwheel 36 integrally secured thereto, rack 35 will shift. This shifting of rack 35 serves to effect rotation 'of gear 21, which rotates gear I8, in the same' direction gear 32 is rotating. Simultaneously, rotation of gear 32 causes rota'- ticn Aof gear 31, and therefore gear 24,. in anl opposit'e direction. Inasmuch as gears I9 and 24 are thus rotated oppositely, it maybe seen that their respective racks will Veffect yshifting of 'carriages 8 and 9 toward Aor away from each other, depending upon the` direction of rotation given to handwheel 36.

To provide for positioning` anvil'A 31', such anvil is secured to slide 38 mounted on 'carriage- 8 for movement therewith and for movement independent thereto. Such anvil 31' is secured to slide 38 by means of thumb screw 39 which frictionally engages shank 40 of this anvil; which is received within opening 4I` of an upwardly-di'- rected projection 42 on such slide.

This slide 88 is supported for independent movement on said carriage 8 by means of balls 43 held in the V-shaped raceways provided therefor. Resilient mounting of said slide is accomplished by spring 44 contained in a recessed opening 45 in carriage 8. Such spring bears against an end of recess 45 and against pin 46 which depends from slide 38. This pin 46 is adapted to be shifted in recess 45, as' will hereinafter `become more clear, to permit such independent Inoveinent of slide 38.

As a means for positioning slide 38 in predetermined location on carriage 8, a bearing plate 41 is anchored to the rearV of carriage 8. Such bearing plate provides an opening v48 therethrough through which stud 49 is permitted to extend to threadably engage' a tapped opening 50 in slide 38. A nut I threadablyengagesthe stud 49 and abuts the rear face of bearing plate 41. Upon tightening nut 5I, slide 38 may be brought into predetermined adjusted position after which lock nut 52 is tightened against nut 5l.

To permit independent movement of'slide'38, it is pointed out that such slide isl not brought tightly against the forward face of bearing plate 41, but some clearance is allowed,` as'indicated in Fig. 2.

Independent movement of slide 381s accomplished by means of eccentric 53. Such eccentric 53 is integral with shaft 54 Whichis jou'rnaled for rotation within bearing 55 in a side wall of carriage 8. A handwheel 56, fixed to a reduced portion 5.1 of shaft 54, may be rotated for" effecting rotation of such shaft. Eccentric" 53 is thereby caused to rotate and in so doing bearagainst an upright leg on bracket '58. inasmuch as shaft 54 is mounted on` carriage' 8, andbra'cket 58 is secured to slide 38', it willbeappreciated that rotation of eccentric 53 serves to cause shiftingof slide 38 independently of carriage 8.

To position anvil' 55 opposite anvil 31, such anvil 59 is secured. toslide 611 mounted on carriage 9. This anvil is securedto slide 6U by means of a thumb screw 6l which frictionally engages shank 62 of this anvil when said shank' is `re'- 6 ceived within opening'63ofvv an upwardly-directed projection 64 lon slidet;

Slide 60 is mounted upon machined surface 65' provided in a groove inthe upper surface of carriage 9` for movement with' the carriage or independent movement with respect thereto. Keeper bars 56 andA 61' overle shoulders 68 and 69, respectively, on said slide 60 to positively maintain said slide within the groove provided therefor in `carriage 9. A lock pin 1U extending through mating openings 1| and 12Y provided inslide El) and carriage 9, respectively, positively locks said members together when it is desirable to move the same as an integrated unit.

In `order to accomplish the independent movement of slide 6'0, lock pin 10 may be movedl upwardly until the bottom of it clearsV the upper' limit of openings 12. After 'pin 1li` has been thus raised, shaft 13 may be rotated byv means of a conveniently accessible handwheel 14 `secured thereto. Rotation of shaft 13 in this manner, causes the integral eccentric 15 on such shaft-to be rotated in opening 16, provided therefor in carriage 81, effecting movement of slide 6B;

To resiliently mount slide 68, carriage 9 provides a recessed opening 11 in which spring 18 lis disposed. Such spring 18 bears against an end of the recessed opening 11- and against pinl 19 to yieldingly hold slide 60 as the-same is moved by means of the eccentric 15'. This independent movement of slide 581s only used when the `gear checker is used to check backlash asr will here-f inafter be described.

To check the pitch diameter of a gear indicatedat 80, anvils 31 and 53 are placed in a desired spaced relationship by means of gage `blocks or other suitable measuring means. This is `accomplished in the lfollowing manner. A dimension M is determined mathematically or by useof tables in the usual handbooks. Such dimension takes into account the diameter of `rolls 8| and 32, which are fixed to anvils 3'1- andv 59, respectively, by jaws in a manner to be later described. Obviously, the diameter of such roll is selected in accordance with the size of the gear to be checked, and such rolls are calculated toi enter a tooth space on such gea-r ai4 predetermined amount. Inasmuch as determination of this dimension M is common practice among gear manufacturers and forms no part of this invention, it will not be further described.

The distance which anvils 31 and 59` are thus` laterally spaced by meansofgage blocks or other suitable measuring is this dimension Mii This spaced relationship of anvils 31and- 551A may be accomplished by means of rotating handwheel to effect shifting of carriages 3 and 9 until the fiat faces of said anvils contact the gage with such pressure as willcause slide 38V tol back up enough to insure proper spring pressure.. At this time, carriages 8 and 9 are locked in position by means of thumb'screws 83 and 845, respectively. Such thumb screwsarethreadably disposed with-A in openings provided therefor in lip 42 olf-the base. portion of the machine and may be turned inwardly to bear against the sides oftheir'respective carriages, locking the same in' adjusted position.

With the anvils properly positioned, and with the gage blocks or other measuring means still in position therebetween indicator is` set to read zero. This indicator is-disposed* in opening 85 provided in cover plate 81- of carriage 8. A pin 38 passes through matingop'enings4 inthe side Walls of carriage 8-V and stem 8'9"l on indicator 85, securing said indicator to the carriage. Such indicator 85 provides a follower 98 adapted to contact screw 8| which is threadably received in the upright leg of bracket 58 secured to slide 38. With screw 9| in contact with follower 90, the indicator dial face 92 is turned So that the pointer 53 on such indicator reads zero. Lock nut 84, on screw 8|, is then tightened against the rear face o f the upright leg of bracket 58 for positively locking screw 8| in predetermined adjusted position against follower 98. After this is accomplished, the gage Yblocks are removed from between `the flat faces of theanvils and slide 38 due to the action of spring 44 will advance slightly. In order to protect the indicator, however, the p-reviously described nut and lock nut 52 are turned to prevent full forward movement of slide 8,8. lThe gage blocks are then re-inserted as a check to insure that, after adjusting nut 5| and lock nut 52, that indicator 85 still reads Zero. After this rolls 8i and 82 are each fixed to its respective anvil.

In order to secure roll 8| to anvil 31, such roll is inserted into double jaw 95. This jaw 85 is positioned within socket 96 provided within collar 97 which threadably engages the annular shoulder 88 of anvil 3l. Obviously, tightening of collar 9i will cause roll 8| to become rigidly positioned against the at face of the anvil. Due to the V in holding elements 95EL and 85b of double jaw 95, roll 8| is held precisely on the center of the flat face of anvil 31, perpendicular to table 5 of base l at the longitudinal center of the gea-r checker.

Similarly, roll 82 is fixed to anvil 58 by means of double jaw 98 which is exactly like double jaw 85 illustrated in Figures 12 and 13 inclusive. Such jaw 83 registers within socket |08 provided within collar |8|. Such collar 18| threadably engages annular shoulder |82 of anvil 58 and upon beingV tightened thereon rigidly fixes roll 82 to the flat face of such anvil. Due to the `V in holding elements 88a and 98h of double jaw 98, roll 82 Vis held precisely on the center of the fiat face of anvil 58, perpendicular to table 5 of base at the longitudinal center of the gear checker. Thus, roll 82 is directly in line with roll 8|. It may now be appreciated that the gage blocks may be inserted between the hat anvil faces simply by removing the rolls therefrom upon loosening the collars. Thus, the apparatus of this invention may be placed in readiness for checking a gear while the means for holding such rolls is mounted thereon.

It is then necessary to determine the interdental spaces on gear 88 in which rolls 8| and 82 are to enter. These are selected in the usual manner; that is to say, visually. Y

After doing so, eccentric 53 is rotated by mea of a handwheel 58 for causing slide 38 to move rearwardly. Gear 8G is then placed between jaws 3l and 59 and slide 38 is returned by means of the handwheel 56 so that the rolls 8| and 82 enter their proper interdental spaces, with the gear resting upon the lower members of jaws 85 and 88, respectively.

Stop |83, slidably supported by bracket |84, is then moved inwardly until the end of said stop is just clear of the teeth of such gear. When this position is reached, thumb screw |85 is turned tight upon stop |83 for locking it in position. Such stop |83 provides a convenient means for locating further gears of the same size or lot to be checked as the same are successively placed in the machine for checking. Bracket |84 which supports such stop is provided with a leg |05 adapted'to extend through an opening in bracket |81 which is integrally mounted on the base of the machine. By means of the arm |08, it is possible to raise or lower stop |03 when it is necessary to accommodate various gear widths. rThis may be accomplished by loosening thumb screw |88 permitting such arm |88 to be shifted in bracket |81 and tightening said thumb screw again when the desired height of stop |83 has been reached.

With the gear to be checked thus positioned between rolls 8| and 82, it will be appreciated that spring 44 carried within the recess 45 of carriage 8 will resiliently urge roll 8| toward roll 82. Inasinuch as this pressure is constant, pins 8| and 82 will be held within the tooth spaces by the same amount of pressure for every gear checked, thereby eliminating any error due to an increase or decrease in this pressure, as is commonly the case, when the gears are checked manually with micrometer and rolls.

In order to remove the gear from the checking apparatus after the same has been checked, it is only necessary to move slide 38 rearwardly by means of the handwheel 55, after which, the gear in the machine may be removed and replaced with the next gear to be checked. Any variation or error in the gear will, of course, immediately be found upon readingr the dial.

In order to use the gear checker of this invention for checking concentricity of gears, it is necessary to alter the same as indicated in Figs. 5 and 6. Thumb screw 6| in projection 64 of slide 88 is loosened, permitting withdrawal of anvil 58 and with it, roll 82 and the elements requisite for holding said roll to anvil 59.

At this time, mandrel |89, having the enlarged portion ||8 upon shoulder I of which the gear to be checked is adapted to be supported, is positioned within the opening provided therefor in locator ||2 and supported therein in an upright position by means of shoulder ||3 on said mandrel. This locator ||2 is positioned within a depression H8 centrally of the gear checking apparatus.

Roll 8| is then brought into contact with the gear between one of the tooth spaces on such gear by means of the handwheel 36 with such pressure as will cause slide 38 to back up enough to insure proper spring pressure. After this has been done, carriage 8 is again xedly positioned by means of the thumb screw 84. Indicator 85 is then set to read zero in the manner described in the foregoing, and the handwheel 58 is turned for moving slide 38 rearwardly. Gear 88 is then turned to another tooth space and handwheel 55 rotated in an opposite direction to bring roll 8| into contact with this tooth space. Any errors will, of course, be read on the dial of the indicator.

To check gears for backlash, the gear checking apparatus of this invention is altered in the following manner. Anvil 58 with roll 82 is removed from slide 58 as previously described. Sleeve H5 is inserted within opening 83 and secured therein by means of thumb screw 8|. Within sleeve |15, arm I6 is pivotally supported at An indicator I8 is mounted by means of stem H9 in an opening provided therefor in slide 88. This indicator ||8 provides a nnger |28 adapted to engage one end of arm ||6 and also has the usual dial face |2| with indicating needle |22 for reading the amount of backlash as the checking operation proceeds.

In order to locate anvil 31 for this operation, it is necessary to` removeroll 8| by loosening collar 91 so that anvilY 31 may again be reset by means of gage blocks. In this case, a figure which is one-half of the previously mentioned M value is used, and from this figure is subtracted onehalf the diameter of mandrel |99, the diameter of mandrel H39, of course, being-taken at the small end upon which gear 89 is disposed during the checking operation. Using the ligure determined in this manner, gage blocks are inserted between the mandrel and anvil 31 which is then tightened against such gage blocks by means of the handwheel 36 with such` pressure as will cause slide 33 to back up enough to insure proper spring pressure. In this manner, the anvil is accurately and precisely located one-half M distance from the center of the gear to be checked. After locating anvil 31 in this manner, carriage 8 is again locked in position by means of thumb screw 94 in the usual manner.

Slide 33 is then adjusted by means of` nut 5| in position such that it will not move when the gage blocks are removed from between mandrel |99 and anvil 31, and locked in this adjusted position by means of the lock nut 52 as it is turned tight yagainst nut The dial on indicator 5 is then set to read zero and screw 9| locked by means cf lock nut 94.

With roll 9| in position, lock plug lil, on slide 99, is moved upwardly until it clears opening 12 in carriage 9 and slide 60 is moved away from the center of the apparatus by means of handwheelM.

At this time, slide 38 is also moved away from the center of the gear checker by means of hanclwheel te and gear St placed upon mandrel |99.

When gear S9 is in position, slide 38 is permitted to return to its previously adjusted position upon rotation of handwheel 55, permitting spring 44 to urge it toward the center of the gear checker. Slide 69 is also returned by means of spring 11 as handwheel 14 is rotated to permit this spring to return such slide. This allows the end of arm IIS, opposite to the end `thereof in contact with finger on gage ||8, to contact a flank of one gear tooth. Indicator I8 may now be adjusted to read zero.

Due to the fact that` gear 80 is cut slightly under size to allow for the backlash determined in the design of such gear, roll 8| will not contact the flanks of adjacent teeth as it enters an interdental space on such gear, but will have clearance equal to the backlash. Thus, it is possible to rotate such gear slightly upon mandrel |09 serving to move lever IIE. Such movement of lever I I6 may be read on dial |2| of the indicator Il, thereby checking the backlash of the gear.

Very often it is necessary to check the pitch diameter of a wide. faced gear or spline having a shaft extending from each side of the gear. In Figure 9, the modifications necessary to the gear checker of this invention `to accomplish such checking are illustrated. In this case, the anvils 31 and 59 are set by means of the gage block in the usual manner. However,` due to the face width of the gear, double jaw members 95 and 99, respectively, which are secured to said anvils 31 and 59 may not be used. Such jaws are replaced with single jaw members |23 and |24 having V form holding elements |23al and |2412 respectively. Jaws |23 and |24, which are similar, are fixed to the respective anvils by means of collars 91 and IIlI in the same manner as were jaws 9.5 and 9e. Such jaws support rolls 8l and 82 in the manner .illustrated in the figure, leaving the upper end of said roll free to permit the same to enter in the proper tooth spaces on a gear to be checked. The gear |25 may be placed between such rolls with either side down, depending upon the shape and length of the shafts, one of which extends through the opening provided in locator H2. Checking such gears after these alterations have been made, is accomplished the same as described in the foregoing. When the shaft of the gear is of such size it will not freely pass through the opening provided in locator I I2, such locator may be removed as the same is not used while the pitch diameter is checked.

In order to check a gear such as gear |25 for concentricity and backlash, it is only necessary to add a bushing |25 in the opening in locator Il?! to support said gear as the same is checked. Other than this and with the modication as i1- lustrated in Figure 9, the operation is exactly the same as previously described.

It is also possible to check helical or herringbone gears on the checking apparatus of this invention. To check helical or herringbone gears, anvils 31 and 59 may be turned in position to mate the angle of the gear being checked. The anvils are, of course, located in the usual manner by means of gage blocks or other suitable measuring means. The rolls are placed in position and moved into the proper tooth spaces, after which the carriages 3 and 9 are located in position by means of the thumb screws. Checking may then proceed exactly as in the case described for the spur gear. However, if the helical angle is too great, it may not be possible to use rolls ill and 52 to accomplish the checking of such gears. in this case, the jaw member |21, as illustrated in Figure 1l, is used. Such jaw |21 has a V-shaped pocket |28 in the lip thereof which is adapted to hold a ball. By replacing the previously described jaws with jaws of the type of jaw |21, and replacing the rolls 8| and 82 with balls adapted to be clamped by said jaws |21, a helical gear having considerable helical angle may be checked in this gear checking apparatus in the same manner as a spur gear.

With the form of the invention` as modified in Figure 2c, it is possible to check gear teeth for parallelism. For this purpose the previously described carriage 9` is replaced by a carriage |29 which has side walls and is generally similar to carriage 8 on the right side of the gage. The previously described slide Gli, for use with carriage 9, is also replaced by a slide ISii mounted on carriage |29. This slide is movable with carriage |29 or independently thereof and for such independent movement is mounted on carriage E29 by means of balls |31 held in the V-shaped raceways provided therefor. Such independent movement of slide I3@ is accomplished against the action of spring |92, which is disposed within recess |33 provided in carriage |29.. One end of spring ist abuts an end of recess |33 and the other end contacts pin IM, which depends from slide its; and when slide |35) is moved independently, spring E32 acts to return the same. The lock pin le previously described in connection with slide eil, is replaced by stud |35 threadably secured to slide |99 and having stop nut |36 and lock nut itil and serve the same purpose as the said pin i9.

In order to provide for independent movement of slide les with respect to carriage |29, eccentric Ille is carried by shaft |39 which is journaled for rotation with bearing Idil in a side wall of carriage |29. A handwheel MI, iixed to the reduced end of shaft |39, may be turned to effect rotation of eccentric |38. This eccentric is adapted to engage the inner face of the upwardly directed lug |42 on slide |38 when rotated, and, inasmuch as such slide is movable with respect to carriage |29 in which eccentric |38 is secured by means of shaft |39, it will be observed that slide |30 will shift independently of such carriage |28.

In order to lock slide |30, so that it may not be thus independently moved, an L-shaped member |43 is positioned on slide |38 with one leg immediately below eccentric |38. The upright leg of this L-shaped member is so positioned that eccentric |38 may be rotated to contact the same and when so contacting such leg, stop nut on stud |35 is brought into contact with bearing plate E44 on carriage |20 and locked by means of lock nut |31.

The upwardly directed lug |42 also provides for mounting an indicator |45. This indicator has the tab |46 depending therefrom which may be anchored to a face of such lug |42 by means of a screw or bolt such as shown at |41.

As a means for mounting anvil |43 on slide |38, an upwardly directed projection |49 having opening |53 centrally thereof is provided. Similar to previously described anvil 59, anvil |48 providesY a shoulder portion |5| to threadably receive collar 0| by means of which jaw 99 is secured thereto for holding roll 82 as previously described in connection with jaw 59. As may be seen in Figure 26, Ia bushing |52 receives shank |53 of anvil |48 and, after passing such shank through bushing |52, lever |54, having an enlarged end which is non-rotatably received by the squared portion |55 on shank |53 is placed in position. This assembly is then mounted on slide |30 by placing the same in opening |50 which is slotted at |56, in the top thereof, to permit lever |54 to pass through. Thus, it will be appreciated that anvil |48 is rotatably mounted on slide |30 and held thereon in a manner to be later described.

As will hereinafter become more clear, this rotative movement of anvil |48 permits a gear to be checked for parallelism of the teeth and for this purpose lever |54 has la pin |51, integral therewith, adapted to contact one end of curved lever 58d. This curved lever is on pivot pin |58, as may be seen in Figure 25, and such pivot pin |58 is pivotally mounted in bracket |60 anchored to slide |30. The other end of the curved lever |5811 contacts follower |G| of indicator |44 and it will be appreciated that oscillatory movement of lever |54 is imparted to lever |58a, causing the same to effect movement of follower |6| serving to cause the pointer |62 of indicator |45 to register the movement of lever |54.

To prevent injury to the indicator, due to too great movement of lever |54, a stop |63 is positioned in the rear face of projection |49 adjacent one side of lever |54. In this manner, that movement of lever |54 which effects actuation of indicator |45 cannot exceed the limit beyond which said indicator |45 may be safely operated.

Thus, when it is desired to check the parallelism of the teeth of gear 80, a tapered pin |54 is passed through opening |65 in slot |56 and permitted to extend through mating openings v|66 and |61 in bushing |52 and shank |53, respectively, to be received by opening |68 in the lower annular surface of projection |48. In the design of this modified form of the present invention, opening |61 in shank |53 is so positioned that when pin |64 is in position, roll 8,2 is parallel (5 to the longitudinal axis of mandrel |69 and perpendicular to the longitudinal axis of the gear checker of the present invention.

After this, carriages 8 and |29 carrying slides 33 and |30 therewith, are shifted by means of handwheel 36 to bring rolls 8| and 82 into contact with the flanks of adjacent gear teeth on diametrically opposed sides of the gear with such pressure as will cause said slides to back up to insure proper spring pressure. Then, by means of thumb screw B3, which in this modified form is located on the rear of the gage, and thumb screw 84, carriages 8 and |29 are locked in position. After locking carriage |29, slide |30 is backed away from the center of the gage by means of handwheel |4|, and indicator |45, which preferably reads .0001 part of an inch, is set to read zero. Tapered pin |64 is then removed and placed in storage opening |69 provided in slot |56 and permitted to extend therethrough to enter a mating opening |10 which is in bushing |52, holding the assembly, consisting of anvil |48, bushing |52 and lever |54, in place on slide |38, but leaving anvil |48 free to rotate. By means of handwheel |4|, slide |30 is then advanced again to bring roll 82 again into contact with flanks of adjacent gear teeth. Should this contact cause anvil |48 to rotate, the indicator will not return to its zero reading, and the operator immediately is aware of the fact that the tooth is not parallel to the longitudinal axis of mandrel 80 and perpendicular to the longitudinal axis of the gage and is therefore incorrect.

It is pointed out that the amount of error read on the indicator is, of course, dependent upon the length of lever |54 and in the gage of the present invention this length is such that the reading on the indicator need only be divided by the face width of the gear to obtain the amount of error for each gear.

When Vit is desired to rotate gear 80 to check another tooth, carriage 8 and slide |30 are moved away from the center of the gage by means of handwheels 56 and |4|, respectively. Gear 80 may then be rotated, and the slides returned by means of the handwheels, after which another tooth may be checked for parallelism. This operation may be repeated as often as the operator desires until all, or any number less than all, the teeth have been checked.

In Figures 23 and 24 the previously described sleeve 5 with arm ||6 pivotally mounted therein is used for checking backlash of a gear with this modied form of the present invention. In this instance, the assembly consisting of anvil |48, bushing |52 and lever |54 is removed from opening |50 in projection |49, and sleeve ||5 placed therein. Previously, sleeve ||5 was held in position by a thumb screw 6|, however, in this modified form, due to the fact that slot |56 is provided in the top of projection |49, sleeve H5 is provided with an opening 10a adapted to mate opening |69 in projection |49, and pin |64 is permitted to extend therethrough holding sleeve I5 in position within opening |50. Assembled in this position, arm ||6 contacts, with its one end, curved lever |581) and with its opposite end, a flank of a tooth on gear 80.

During this backlash checking operation, slide |36 may be moved by means of hand wheel |4| to take arm ||6 out of contact with a flank of a tooth of gear 80 and at the same time slide 38 moved by means of handwheel 56 away from the center of the checker to bring roll 8| out of contact with gear 80, ',Ihis leaves said gear 80 free so that the same may be rotated, after lwhich arm IIS and roll 8l are again advanced toward the center of the `checker in order that backlash may be checked at various points on the `circumference of the gear. It will be appreciated, therefore, that the movement of arm ll in .contact with the gear flank will be imparted to lever |5817 and through pivot pin |59 and lever |5811 to fcllower of indicator |45, such indicator being set to read Zero as described inthe foregoing .and registering thereon the amount of backlash of the gear.

A modincationof the arm for use in sleeve H5 is illustrated in Figure 27. In this case, an arm is illustrated which is adapted to be mounted within sleeve ||5 in the same manner as arm H6 for pivotal movement about a central point. However, arm |1| has the shiftable end |12 which is pivoted at |13 and may be so moved as to bring end |72 thereof into contact with a tooth flank in which the interdental spaces of a gear are quite Ierse due to the `Size of Such gear- As a further improvementto the checker of the present invention, a scale I'M has been added, as may be seen in Figures and 23. A pointer for use with scale |14 is provided on carriage and the scale IM so graduated that it indicates `the total distance between the flat faces of the anvils. By using this scale, an operator may adjust Vthe anvils, according to the size of f the gear or part to be checked, into a position such .that the proper spring pressure will be exerted by the rolls or anvil faces against the part to be checked `without resorting to trial or error.

Substitution of slide i3d for slide i583 does not alter in any Way the ychecking operation for checking pitch diameter of a gear. In such operation, the procedure is exactly the same as that `described in the foregoing in connection with slide 60 and is not here aga-in described.

The gear checker of the present invention may also be used to check tooth spacing. For this operation either slide 6) or the modified slide |313 may be used. In order to check tooth spacing, stop nut 5| is moved away from bearing plate ll releasing slide 38 from the position to which the same was adjusted for checking backlash. This adjustment of slide 38 has been described in the foregoing and is n-ot here further described. This release of slide 38 allows roll 'il on anvil 3l to contact the ii'anks of adjacent teeth of gear 89. Slide i3d is then moved to bring arm It of sleeve ||5 into contact with a flank of a tooth on gear Si) `and indicator Ilil set so that pointer |62 reads zero. After this, slides 3'3 and |323 are moved away from gear @il by means of handwheels 55 and Ml in the usual manner, freeing gear Sil so that the same may be rotated. Then roll Si and arm i6 are again brought into cont-act with flanks of diametrically opposed teeth by means of the handwheels. Indicator |51 should again read zero, indicating that the teeth are properly spaced. If indicator |5| fails to read zero, the operator is made aware of the fact that the teeth are not properly spaced.

It Will be clear from the foregoing description that the gear checking apparatus shown in the drawings and described above has been illustrated and described in rather specific detail. Obviously, many modifications, changes, and departures from the above described construction may be made without departing from the generic spirit and scope of the invention as set forth in the subjoined claims.

What is claimed is: t

r1. Gearcheckingapparatus comprising, a base, Ia pair oi opposite, A,movable carriages `mounted on said base, `means to ,eifect simultaneous movementof Asaidcarriages longitudinally of the base and relatively to eachother, a slide mounted for independent sliding :movement on each of said carriages, a flat face-,anvil mounted `on each slide, vthe face of .each -anvil .being directed inwardly .toward the other of said anvils,.mounting means on each anvil adapted to secure a roll :against a respective anvil face, said mounting means also adapted to Vsupport a gear to be checked, and a spring bearing against one `of said slides to urge the anvil carried by said-slide toward the opposite anvil to press the rolls .on the anvils with. Constant pressure against adjacent tooth flanks as said -rolls entel diametrically opposed interdental spaces such .gear to be checked.

`2. Gear checkingapparatus comprising, a base, a pair of opposite, movable carriages mounted on said `base, means `to effect .simultaneous movement `Orf :said lcarriages longitudinally of said base relative to each other, slides mounted on the carriages i101' `Iidf-peld.ent movement thereon parallel to the direction of travel thereof, a flat face anvil mounted Aon each slide, and the face of each anvil being `directed toward the center of the base, mounting lmeans having roll-fastening means covering no more than a small part of the anvil faces and permitting entry of gage blocks between the opposite anvil faces to accurately position the same `before the rolls are placed therein, and a gage operatively associated with one lof said `anvils to indicate errors as a gear to be chekd is introduced between said rolls.

3. Gear checking apparatus comprising, a base, a pair of opposite, movable carriages mounted on said base, means to effect simultaneous movement of said carriages longitudinally of the base toward or away from the center thereof, a slide mounted on each carriage for movement therewith or independent slidable movement thereon toward or away from the center of the base, a dat face anvil carried by each slide, the face of each anvil being directed toward the center of the base, a threadably supported collar on each anvil, a jaw member to be received in each collar, a roll in each jaw rigidly secured to the face of its -respective anvil when such collars `are tightened, said jaws permitting entry' of gage blocks between the opposite anvil faces to accurately -position said faces before the rolls are placed therein, said jaws adapted to support a gear to be checked as the rolls enter diametrically opposed nterdental spaces in such gear.

4. Gear checking apparatus comprising, a base, a pair of opposite, movable carriages mounted on said base, means to effect simultaneous movement of said carriages longitudinally of the base toward or away from the center thereof, a slide mounted on each carriage for movement therewith or independent slidable movement thereon toward or away from the center of the base, a .pair of flat face anvils disposed one to each slide with the faces thereof directed toward the center of the base, Ia threadably supported collar on each anvil, a jaw member to be received in each collar, a roll in each jaw rigidly secured to the face of its respective anvil when said collars are tightened, said jaws permitting entry of gage blocks between the opposite anvil faces to accurately position the same before the rolls are placed therein, said jaws adapted to support a gear to be checked, a, spring in one of said carriages, said 15 spring operatively associated with the slide on said carriage to resiliently urge said slide to move independently on said carriage toward the opposite slide thereby eifecting the rolls to exert constant pressure against yadjacent tooth flanks as the same enter diametrically opposed interdental spaces in the gear to be checked, and an eccentric mounted on said slide for moving the same independently of the carriage against the action of the spring for loading or unloading a gear to be checked.

5. Gear checking apparatus comprising, la base, a pair of opposite, movable carriages mounted on said base, means to eifect simultaneous movement of said carriages longitudinally of the base toward or away f-rom the center thereof, a pair yof at face anvils mounted one to each carriage with the face of each anvil directed toward the other of said anvils, said anvils being manually rotatable about their longitudinal axis, and mounting means on each anvil for securing gaging body against the flat face of each anvil, said at anvil faces having exposed areas permite ting gage blocks to be inserted between the op- Iposite Iat faces of the anvils to accurately position the same before the gaging bodies are placed therein, said mounting means also adapted to support a gear to be checked as the gaging bodies enter diametrically opposed interdental spaces in such gear.

6. In a gear checker, :a pair of opposite, movable slides, means to move said slides in unis-on toward or away from each other, a pair f at face anvils mounted one to each slide and movable therewith, said anvils being disposed so the at face of each anvil is directed toward the face 16 of its opposite and the faces of the anvils dening reference surfaces for conventional measuring and spacing means such as Jo blocks and the like incidental to setting the machine for operation, roll mounting means on each anvil adapted to securely fix a roll to the at face thereof, said mounting means having roll-fastening means covering no more than a small part of the anvil faces and so arranged that gage blocks may be positioned between the anvil faces before the rolls are xed thereto while said mounting means are in position, and resilient means bearing against one of said slides to urge the same toward the opposite slide thereby causing rolls carried by l5 the anvils to exert a uniform pressure on the anks of teethof a gear to be checked as said rolls enter diametrically opposed interdental spaces on such gear.

AMERICO S. ORLANDI.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name Date 335,214 Corb Feb. 2, 1886 1,392,313 Fallow Oct. 4, 1921 1,667,562 Neubauer Apr. 24, 1928 1,854,244 Allison Apr. 19, 1932 1,910,467 Heckersdore May 23, 1933 2,199,236 Bigwood Apr. 30, 1940 2,431,021 Bourdelais Nov. 18, 1947 2,445,402 Malmberg July 20, 1948 Widen Aug, 17, 1948 

